Thread guard for caster wheels



Sept. 26; 1950 E. M. HEFFERN-AN 2,523,659

mman GUARD FOR cAsTER WHEELS Filed Aug. 21, i948 INVENTOR EDM/AanM'HEn-:RNAN

linfa? ATTO NEYS Patented Sept. 26, 1956 THREAD GUARD FOR CASTER WHEELSEdward M; Heiernan, Monson, Mass., assigner to Jarvis & Jarvis, Inc.,Palmer, Mass., a corporation of Massachusetts Application August 21,1948, Serial No.`45,507

2 Claims. 1

This invention relates to improvements in caster wheels and threadguards for the axles of the same and has for an object a simplifiedconstruction of Wheel assembly characterized by efficiency in operationand economy of manufacture.

Such guards are commonly used on caster Wheels to prevent anaccumulation of thread or lint in the axle bearing of a wheel when thesame is used in a textile mill, dry cleaning establishlment or otherlocation where loose threads or refuse lint, etc., is likely tocause anaxle to bind and stop the rotation of the wheel.

`Generally the guards are in the form of dished washers mounted on theaxle on each side of the wheel between the wheel and each fork arm. Sofar as I am acquainted with the prior art, almost universally it hasbeen the practice in the trade to mount a spacer bushing on the axlebetween the two guards. The axle nut and bolt is then drawn tightly,forcing the guards against the spacer ends to thereby press the guardsagainst rotation with the wheel. Accordingly, the spacer must beprecisioned more or less accurately to insure correct dimensions in agiven wheel assembly and to enable proper operation thereof. This typeof construction has not been -reconomical from the standpoint ofmanufacturing costs nor has it lent itself to speed in assemy blyoperations. It is not an assembly which can readily be adapted tosupplement a standard caster wheel construction.

It is an object of this invention to eliminate the necessity of a spacerelement in the caster wheel to be equipped with thread guards. only doesthe new construction eliminate this part but in addition it eliminatesthe necessity of precision handling in relation to the entire assembly.

A further object is to provide an article whic is adapted for mountingon a standard wheel without the need for excessive reworking of the sameto accommodate the addition of guards. The new guard may thus be easilyadapted for caster wheels at their location of use in the field.

These and other objects and advantages will become apparent from aconsideration of the following description and accompanying drawings, inwhich Fig. 1 is a side elevation of a caster embodying the features ofmy invention;

Fig. 2 is an end elevation of Fig. 1;

Fig. 3 is a cross section on line 3-3 of Fig. l;

Fig. 4 is a side elevation of the dished thread Y guard washer;

lNot

Figs. 5, 6, 7 and 8 are elevational views showing modifications in themeans of locking the guard washers to the forks of the caster yoke; and

I Fig. 9 is a side elevational view of the end of one caster fork.

In the caster Vconstruction as shown generally in Figs. 1 and 2 andinmore specic detail, in Fig. 3, a rubber wheel IU is rotatably mounted ina yoke II having spaced forks I2 and a flat top vplate orrplatform I3.-A caster stem I4 is swivelably attached to yoke platform I3, as forexample by the arrangement illustrated, wherein a flange I5 at the endof the stem abuts the-bot,-

tom of the'yoke platform, and a bearing cap I6 rmly attached to the bodyof the stem holds ball bearings I'l against the top of the yokeplatform. The present invention, however, is `not concerned with thecaster stem or its attachment which may be of any suitable design, butonly with the mounting of wheel IIl in yoke EI.

Rubber Wheel I0 preferably has a graphited bushing I8 (Fig. 3) liningits `bore for rotation of the wheel on a stationary Wheel axle I9. Thisaxle extends through one yoke fork I2, the washer or thread 'guard 20,the rubber Wheel II), the second thread guard, and the second fork I2.

The term thread guard or thread guard washer is commonly used in theindustry for devices'applied to or used with the caster Wheel to preventthreads, dirt, lint or other foreign matter from being picked up,accumulating, and bind- 'ing the wheel against rotation. This term isapplied to dished Washer 2li herein to describe its most usefulfunction, i. e. preventing threads from wrapping around the caster axlein textile mill or laundry use.

The wheel axles flattened head portion 2 I4 with lug 22 (Fig. 3') andthreaded end 23 with nut 24 provides means for squeezing yoke forks I2together to hold the thread guard washers closely adjacent to the wheeLyWheel I0 has hub portions 25 on each face to abut the flat centerportion of the dished thread guard washers and a groove 26 cut or moldedin each face to receive the peripheral edge of the washers. As shown inFig. 3 the peripheral edge of each thread guard washer ts into acircular groove 26 so as not to touch or bind the wheel.

To hold the dished thread guard washers against rotation with the wheel,two brackets as ears 2l are stamped or punched from the metal of thefiat center portion. The ears fit snugly against the edges of the forksnear the bottom of the yoke when the Washers are placed in po asaaesothe nut put on its threaded end and then tight--l ened to complete theassembly.

One of the axle holes 28 through the forks' should preferably be cutwith a flattened edge 28e as shown in Fig. 9. The cornersv 'ofthisflattened edge will then receive lug 22 on the axle and positivelyprevent roqtation of the axle. The friction between the surfaces of theaxle nut 2'4 and its adjacent yoke fork will also aid vin this function.

In the preferred embodiment of the invention asillustrated in Figs.`1,2, 3, and 4, twoY of the ears `21 are provided on each thread guardwasher. These ears need only be of a length to adequately abut the edgesof yoke `forks I2 (i. e. onlyv slightly longer than the edge thicknessof the metal). And it will be noted that the openings in the surface oftheguard metal from which the ears are Ypunched are angled so as tounderlie the edge of fork arm l2 and prevent the introduction of dust,etc. The ears, moreover, may be made long enoughA for each to be bentover the edge'of a forkvas shown in Fig. 5. When bent over, the ears 21aprevent axial movement of the thread guard washer as yof Fig. 7combining the'two ears offFig. 1 and the hole and ear arrangement ofFig. 6; -or that of Fig. 8 whereinears are yprovided on the yoke forksvto engage holes 3D punched inthe thread guard washers.

The invention is particularly adapted to'improve standard casterequipment now in use. The dished thread guard washers may -be supplied`suitably punched or stamped and of a size to fit grooves which may beprovided in any standard caster wheel. The guards may also be of anydiameter desired with relation to the wheel diameter. The size shown bythe drawings is considered preferable as having its outer edgeapproximately half way ebetween the hub 4 of the wheel and its outerperiphery. It might be of lesser diameter or of a size to cover theentire side wheel face.

What I claim is:

1. A caster assembly having forked arms, an axle carried between saidarms and of uniform diameter from arm to arm, said axle at one endhaving a bolt head for abutment against one arm andI a' shouldered'threaded portion at the other end; a nut on said threaded end to clamplsaid other arm against the shoulder of said axle and prevent movementof said latter arm toward the first arm a wheel mounted on said axlewith Va raised'y hub portion at each side of said wheel, f the crosssectional'shape of the wheel taken on aplane which includes the axis ofrevolution of the wheel being substantially rectangular, and threadguards in the form of circular washers mounted on a each side of thewheel between an arm and its adjacent hub, said guards having-.earedtabs offset centrally and struck outwardly from the bodyv thereof andlying at each side of thefadjacent arm anda peripheral yflange on eachwasher turned inwardly towards said wheel,l said wheel having circulargrooves in the walls thereof to receive the edges of said guards inslightly spaced'relation.

2. Athread guard construction -for castershaving forked arms carrying anaxle of uniform diameter from arm to armfand a one-piece wheel 'with acentral raised hub portion mounted for arm whenvsaid guardlisrmounted onthe axle, and

an inwardly turnedperipheral `flange on said lguard to lie in closelyspaced relation withrthe side wall of said wheel.

EDWARD M. I-IEFFERNAN.

REFERENCES CITED The following referencesareoffrecord in the le of thispatent:

UNITEDV STATES PATENTS Number Name Date 1,153,838 Bower et al Sept.14,:1915 1,285,142 Happensack Nov. 19, 1918 1,861,539

Lilly June 7, v1932

